I agree with SpotstheCat. Breast-fed babies can produce bright, frothy green poo, usually because they are getting too much foremilk or because mum is swapping from breast to breast during feeds. Try feeding from just one breast at a time until the breast is drained to make sure your baby is also getting the rich hindmilk.
Green poop in kids can be alarming, but it usually not a cause for concern. Diet, such as eating leafy greens, often causes green poop. Otherwise, it may be linked to diarrhea or bacterial infections. Poop is usually brown, but it can change color daily.
https://www.medicalnewstoday.com/articles/327218#poop-colors-and-causes

I’d see your gp

It sounds very strange and l would visit a doctor!

The advise I was given was If you see bright green and frothy poop in your baby’s diaper, almost like algae, she’s probably getting too much foremilk – the low-calorie milk that comes first in a feeding – and not enough hindmilk, the good higher-fat stuff. It could mean that you’re not feeding her long enough on each breast. If you are bottle feeding it could be from the extra iron.

There is a poo chart and finder on Babycentre. My computer is playing up a little or I would’ve searched for you. Depending on what his diet is, now if he’s breastfed he shouldn’t be having green poo, although it isn’t exactly too uncommon, my sisters baby had a wee bit of green poo at one stage. My baby is formula fed, with certain formula’s he has green poo, change in formula green, it can happen just randomly as well. Keep and eye out and record how many times this happens. I would give health direct a call myself and just ask, no need to run to the doctors as they can tell you all possibilities and what is your next bet. :). Also make sure that you encourage more fluids if diarrhoea is present, so don’t need to water anything down, just feed and offer feeds more frequently.

Doesn’t sound right but I was always told the only time to worry is when their poo is tar black or Snow White. Is your Bub on breastmilk? Green poo can mean too much fore milk and not enough nutritious creamy stuff.

I would defiantly go and see the doctor.

oh just saw that this question is from awhile ago so hope that bub is doing well

I would suggest you visit your GP as poo can be green for a variety of reasons and for peace of mind it is best to get it checked.

Please go see your gp. I don’t want to speculate. My son had green poo’s for a while and it was all normal and it passed- mind the pun

Not sure of the reason of this happening there could be many causes. But i found a guide on baby center. tittled Baby poop: A visual guide. If concerend at all ring your local health nurse centre. They woud of heard it all before and could help you with your concern.

Thankyou shay for taking the time to write such a detailed response. It has been helpful and I will definitely check that site out right now.

It’s harder to tell with a baby that’s not on food yet. I know when they are eating food green generally means lack of food. My LO has had green poo through a bout of mild gastro and was hardly eating anything hence the green poo.
It can also be an indicator of and allergy most likely dairy. My LO had it until I gave up dairy whilst bc and it went away. Either Once bulbs is feeling better I am sure it will go away. Look up Royal children’s hospital website they have a fact sheet on dehydration if your worried.If it doesn’t get better I’d look into a dairy intolerance/ allergy.
Good luck!!!